340 spine is out of the question if you ask me they will be far too stiff.
.400 is probably the appropriate choice .... if you're set on that insert weight and point weight, I'd bareshaft tune by starting with a full length shaft and cutting 1/4" off at a time.
I prefer to use standard diameter carbons because they accept brass screw in insert weights (they screw into the back of the insert from the nock end). This way I can choose an arrow spine and length and point weight, then tune by adding brass weights behind the insert.
axis shafts with the HIT insert is too narrow for this. You'll have to adjust the shaft length to get the proper spine.